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 #include <bits/stdc++.h>
 using namespace std;
 typedef long long ll;
 const int M = 1e5+;

 int n;
 ll a[];
 int main() {
     a[] = ;
     a[] = ;
     a[] = ;
     for( int i=; i<=; i++ )
         a[i] = a[i-]+a[i-];
     while( ~scanf("%d", &n ) )   {
         printf("%I64d\n", a[n] );
     }
 }